Pérez-García Daniel, Larios-Serrato Violeta, Rojas-Rios Rogelio, Otero-Olarra Jorge Erick, Mendoza-Sanchez Itza, Curiel-Quesada Everardo, Pérez-Valdespino Abigail
Departamento de Bioquímica, Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala S/N, Col. Santo Tomás, CP11340 Mexico City, Mexico.
Department of Environmental & Occupational Health, Texas A&M University School of Public Health, United States of America.
Plasmid. 2021 Nov;118:102607. doi: 10.1016/j.plasmid.2021.102607. Epub 2021 Nov 17.
Plasmids are autonomous genetic elements ubiquitously present in bacteria. In addition to containing genetic determinants responsible for their replication and stability, some plasmids may carry genes that help bacteria adapt to different environments, while others without a known function are classified as cryptic. In this work we identified and characterized plasmids from a collection of mesophilic Aeromonas spp. (N = 90) isolated from water, sediments and fish. A total of 15 small plasmids ranging from 2287 to 10,558 bp, with an incidence of 16.7% (15/90) was found. Plasmids were detected in A. hydrophila (6), A. veronii (4), A. taiwanensis (2), A. jandaei (1), A. media (1) and Aeromonas sp. (1). There were no large or megaplasmids in the strains studied in this work. Analysis of coding sequences identified proteins associated to replication, mobilization, antibiotic resistance, virulence and stability. A considerable number of hypothetical proteins with unknown functions were also found. Some strains shared identical plasmid profiles, however, only two of them were clones. Small plasmids could be acting as a gene repositories as suggested by the presence of a gene encoding for a putative zonula occludens toxin (Zot) that causes diarrhea and the qnrB gene involved in quinolone resistance harbored in plasmids pAerXII and pAerXIII respectively.
质粒是普遍存在于细菌中的自主遗传元件。除了含有负责其复制和稳定性的遗传决定因素外，一些质粒可能携带有助于细菌适应不同环境的基因，而其他功能未知的质粒则被归类为隐蔽质粒。在这项研究中，我们从分离自水、沉积物和鱼类的嗜温气单胞菌属菌株（N = 90）中鉴定并表征了质粒。共发现15个小质粒，大小在2287至10558 bp之间，发生率为16.7%（15/90）。在嗜水气单胞菌（6株）、维氏气单胞菌（4株）、台湾气单胞菌（2株）、詹氏气单胞菌（1株）、中间气单胞菌（1株）和气单胞菌属（1株）中检测到了质粒。本研究中所研究的菌株中没有大质粒或巨型质粒。对编码序列的分析确定了与复制、转移、抗生素抗性、毒力和稳定性相关的蛋白质。还发现了大量功能未知假想蛋白。一些菌株具有相同的质粒图谱，但其中只有两株是克隆株。小质粒可能充当基因库，分别存在于质粒pAerXII和pAerXIII中的编码假定小带闭合毒素（Zot）（可导致腹泻）的基因和参与喹诺酮抗性的qnrB基因表明了这一点。
